POS0667 KNOWN AND LESS KNOWN COMORBIDITIES IN AXIAL SPONDYLOARTHRITIS – WHAT ARE WE OVERLOOKING? RESULTS FROM THE SPARTAKUS COHORT
Authors: J. Sagard, E. Mogard, E. Lindqvist, A. Jöud, M. Geijer, J. K. Wallman, T. Olofsson
Journal: Annals of the Rheumatic Diseases (2023)

<h3>Background</h3> It is well-established that axial spondyloarthritis (axSpA) is associated with extra-musculoskeletal manifestations such as anterior uveitis, psoriasis, and inflammatory bowel disease (IBD). Although relevant data exists also regarding other specific comorbid diseases, less is reported on the overall comorbidity burden in relation to the background population. <h3>Objectives</h3> To assess the frequency of a wide range of comorbidities, covering most important organ-domains and conditions, in a population-based axSpA cohort, including both non-radiographic (nr-axSpA) and radiographic (r-axSpA) disease, and to compare this to frequencies among matched general population comparator-subjects. <h3>Methods</h3> We included 246 well-characterised axSpA patients (mean age 52 years; 55% male) with established disease from the SPARTAKUS cohort, comprising patients from a defined area of southern Sweden. All patients had undergone a thorough clinical assessment and were classified as nr-axSpA (fulfilling ASAS nr-axSpA criteria; n=82) or r-axSpA (meeting modified New York/ASAS r-axSpA criteria; n=164). Furthermore, for each axSpA patient, 5 comparator-subjects from the general population, matched on sex, age, and residence area, were randomly drawn from the Swedish Population Register (n=1230). The frequency of 55 different comorbidities, covering most important organ-domains, were then investigated through ICD-10 diagnostic codes retrieved from the Skåne Healthcare Register (covering both primary and specialised care) and collected during a 10-year period preceding inclusion in the cohort (for the index cases; and during the same period for their respective comparator-subjects). Univariate logistic regression was used to compare frequencies of the various comorbidities between axSpA patients and comparator-subjects, while employing the Benjamini-Hochberg procedure to account for multiple tests. Comorbidities with &lt;5 events in either group were excluded from the analysis (n=12). <h3>Results</h3> Characteristics of the included patients are displayed in the <b>Table 1</b>. Numerically, almost all investigated comorbidities were more frequent among axSpA patients than comparator-subjects (<b>Figure 1</b>). The patients showed a significantly higher frequency of known extra-musculoskeletal manifestations: anterior uveitis (28% vs. 1% for comparator-subjects, p&lt;0.001), IBD (10% vs. 1%, p&lt;0.001), and psoriasis (10% vs. 3%, p&lt;0.001). Also, previously less investigated conditions such as degenerative disc disease (17% vs. 6%, p&lt;0.001), fibromyalgia (12% vs. 3%, p&lt;0.001) and nephrolithiasis (8% vs. 3%, p&lt;0.001) were clearly overrepresented. In addition, patients displayed higher proportions of well-known side-effects of NSAIDs: gastritis (21% vs.10%, p&lt;0.001) and hypertension (31% vs. 19%, p&lt;0.001); as well as glucocorticoids (GC): cataract (11% vs. 7%, p=0.010), glaucoma (7% vs. 3%, p=0.008) and vertebral compression (4% vs. 1%, p=0.002); and more patients had been hospitalised for infections (10% vs. 5%, p=0.006). <h3>Conclusion</h3> When assessing a wide range of comorbidities, contemporary axSpA patients have markedly more morbidity than the background population, with an expected overrepresentation of known extra-musculoskeletal manifestations, but also of less explored conditions such as fibromyalgia and nephrolithiasis, that warrant attention and proper management. Although oral GCs are generally not recommended in axSpA, our results underscore that conditions known as side-effects of such medications are common also in this diagnosis, and that treatments need to be closely monitored. <h3>REFERENCES:</h3> NIL. <h3>Acknowledgements:</h3> NIL. <h3>Disclosure of Interests</h3> Jonas Sagard: None declared, Elisabeth Mogard Speakers bureau: AbbVie, Novartis, Elisabet Lindqvist: None declared, Anna Jöud: None declared, Mats Geijer Speakers bureau: AbbVie, UCB, Johan K Wallman Speakers bureau: AbbVie, Amgen, Grant/research support from: AbbVie, Amgen, Eli Lilly, Novartis, Pfizer, Tor Olofsson Consultant of: Eli Lilly, MSD.